Induction-motor.



No. "718,697. PATENTED 14mm, 1903..

c. 0. OHESNEY.

INDUCTION MOTOR.

APPLICATION FILED JULY 30, 1902.

H0 MODEL.

' BSHEETS-SHEET 1.

' witmaooeo 8W1 CUMMINQS C. GHESNEY f PATENTED JAN. 20, 1903. 0. 0.. OHESNEY.

INDUCTION MOTOR.

APPLICATION FILED JULY so, 1902.

No MODEL. v v 2 SHEETS-SHEET z.

SMUQ/VWOZ 2'- Cumamss C. CHESNEY,

35 mi e aw UNITED STATES PATENT OFFICE.

CUMMINGS O. OHESNEY, OF PITTSFIELD, MASSACHUSETTS.

INDUCTION-MOTOR.

.SLEEGIEICATION forming part of Letters Patent No. 718,697, dated. January 20, 1903.

Application filed July 30,1902.

I'o (tZZ whom. it Wmy concern.-

Be it known that I, CUMMINGS O. CHESNEY,

' a citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Induction-Motors, of which the following is a full, clear, and exact description.

My invention relates to electric-motor construction, and particularly to armatures for induction-motors.

It has for its object to provide an armature which shall be simple and durable in construction and besides being of good general design have a high efficiency and a good starting torque.

A form of armature heretofore used in induction-motors and known as the birdcage armature has the advantage of mechanical simplicity. In such armatures, however, the convolutions or circuits do not act independently-t'. a, the parts of each convolution upon which the field of the motor acts do not constitute an independent part for the current of that convolution, but each such part constitutes a substantial portion of the path for currents from two or more induced circuits. In the winding herein described, however, the conductor of each convolution furnishes a path for the current induced in that convolution and that current only, the armature, at the same time being of simple and durable construction. It consists in a structure adapted to provide such independence and as shown in the drawings accompanying this specification.

An armature for a two-pole motor embodying my invention is shown in the accompanying drawings, in which- Figure 1 is a view of one end of an armature. Fig. 2 is a view partly in longitudinal section. Fig. 3 is a View of the other end of the armature. Fig. 4 is a perspective view of a detail. Figs. 5 and 6 are end elevations of an armature for a four-pole motor.

Referring more particularly to the drawings, A is a core made up of laminated punchings, those in the present embodiment being made with an unequal number of tunnelslots B.

C G are the convolutions or coils formed so Serial No. 117,723. No model.)

the radially alternate portion of adjacent slots. The open ends or limbs of the U are extended through the core to the same side and are there connected together by a continuous conducting-ring D, to which they are secured either by soldering or some suitable adjustable fastening, or both, .the two sides of one convolution being situated on different sides of the ring. The structure thus assembled may be mounted upon a suitable shaft E. The arms of the convolutions are suitably insulated from each other and the core, so as to substantially confine the currents to the separate convolutions. The structureis simple and strong and hasa good torque at starting. When a four-pole motor is used, the windings are duplicated, overlapping at one end, as in Fig. 5. The conducting-ring connects their other ends the same as in the tWo-poletype motor of Fig. 2. The independence of the parts acted upon by the field is still maintained. By reason of this construction the effect of each convolution acting independently is obtained, which is of particular importance, since to get the best effect each convolution should be an independent part of the current. Such a construction gives abetter starting torque than the bird-cage armature and at the same time has the mechanical advantage of simplicity of construction.

What I claim is 1. In an armature for an induction-motor, the combination of an armature-core, separately-formed conducting U -shaped pieces therein, and a conducting-ring to which the ends of said U-shaped pieces are secured.

2. In an armature for an induction-motor, the combination of a core having slots therein, separately-formed U-shaped conductors located in said slots and a ring connecting the ends of said U-shaped conductors.

3. In an armature for induction-motors,the combination of a core having tunnel slots, separately-formed U-shaped conductors located therein, and a conducting-ring secured to the ends of said U-shaped conductors.

4. In an armature for induction-motors,the combination of alaminated core, symmetrically-arranged U-shaped conductors embedded therein, and a conducting-ring to which the ends of said U shaped conductors are connected.

5. In an armature forinduction-motors,the combination of a magnetic core, separatelyformedU-shaped conductorsembedded therein, and an iron ring to the opposite sides of Which the ends of said conductors are secured.

6. In an armature for induction-motors, the

CUMMINGS O. OHESNEY.

\Vitnesses:

H. H. MILLER, E. HEITMANN. 

